What Is A Caster?

A caster is an entire assembly that consists of at least a wheel, axle, fork, and mount. Casters are typically un-driven, and are used to make applications easier to move around by rolling them.

There are hundreds of types of wheels including hard plastic, soft rubber, and solid metals. These wheels can be various shapes as well, for example, ball wheels, crown tread wheels, and v-groove wheels.

There are also many axle and bearing combinations that can be used on a caster.

Forks, sometimes known as yokes or brackets, are available in two main types: swivel and rigid. A swivel caster may rotate to change direction, like those found on the front wheels of a shopping cart. A rigid caster remains in a fixed position and cannot rotate freely, like the rear wheels of a shopping cart. Swivel casters are designed with an offset, to make turning and changing direction easier, while rigid casters are generally directly below their attachment point.

Mounts are also extremely varied depending on the application. Smaller casters tend to use stems which insert into the application. Larger casters almost exclusively use a top plate.

Common options on casters include brakes and locks. Brakes, usually operated by the foot, prevent the wheel or wheels from rolling. Some brakes include a locking mechanism which will stop a swivel from pivoting.

What is a Caster?


Basic Caster Components


1: Connection type. In this case, a grip neck stem.


2: Swivel joint. (Shown: Ball Bearing Raceway)


3: Brake option. (Shown: Top Lock Brake)


4: Fork. (Shown: Zinc Plated Steel fork assembly)


5: Axle. (Shown: Bolted Axle)


6: Wheel. (Shown: Rubber on Polyolefin)